The present invention is directed to a device for monitoring chip temperature of a switch output stage having a switch element. The switch output stage is formed by all switch arrangements with one or more active switch elements, particularly full-bridge arrangements (H-bridges) with four active switch elements, half-bridge arrangements with two active switch elements and arrangements having an individual active switch (for example, inductance transducer for amplification of an input voltage). In particular, the present invention is directed to switched amplifier output stages, preferably in a gradient amplifier of a magnetic resonance tomograph.
A device for monitoring chip temperature is particularly acquired in switch output stages when high powers are switched. The barrier layer temperature (or the chip temperature in a more general and simpler terms) of the switch elements is decisive for the dependable and long-lived operation of an output stage. The chip temperature must therefore be identified in realtime during operation of the switch output stage in order, for example, to be able to reduce the power or switch the output stage off when critical temperatures are reached.